Project description:Plants possess various defense strategies to counter attacks from microorganisms or herbivores. For example, plants reduce the cell-wall-macerating activity of pathogen- or insect-derived polygalacturonases (PGs) by expressing PG-inhibiting proteins (PGIPs). PGs and PGIPs belong to multi-gene families believed to have been shaped by an evolutionary arms race. The mustard leaf beetle Phaedon cochleariae expresses both active PGs and catalytically inactive PG pseudoenzymes. Previous studies demonstrated that (i) PGIPs target beetle PGs and (ii) the role of PG pseudoenzymes remains elusive, despite having been linked to the pectin degradation pathway. For further insight into the interaction between plant PGIPs and beetle PG family members, we combined affinity purification with proteomics and gene expression analyses, and identified novel inhibitors of beetle PGs from Chinese cabbage (Brassica rapa ssp. pekinensis). A beetle PG pseudoenzyme was not targeted by PGIPs, but instead interacted with PGIP-like proteins. Phylogenetic analysis revealed that PGIP-like proteins clustered apart from classical PGIPs but together with proteins, which have been involved in developmental processes. Our results indicate that PGIP-like proteins represent not only interesting novel PG inhibitor candidates in addition to classical PGIPs, but also fascinating new players in the arms race between herbivorous beetles and plant defenses.
Project description:The 5th and 6th leaf blades of the rice Os-LBD37 overexpressor line RK16331-13 and the empty vector control line FOX3 were examined. LBD37 belongs to the plant- specific LOB- (Lateral Organ Boundary) domain family proteins first characterized in Arabidopsis. Results point towards an involvement of the rice LBD37 (OsLBD37) ortholog of Arabidopsis in nitrogen metabolism- and senescence- related processes.
Project description:The 5th and 6th leaf blades of the rice Os-LBD37 overexpressor line RK16331-13 and the empty vector control line FOX3 were examined. LBD37 belongs to the plant- specific LOB- (Lateral Organ Boundary) domain family proteins first characterized in Arabidopsis. Results point towards an involvement of the rice LBD37 (OsLBD37) ortholog of Arabidopsis in nitrogen metabolism- and senescence- related processes. Hygromycin- resistant rice Os-LBD37 overexpressor and empty vector control plants were grown in hydroponic culture system. The sampling date of the leaf blades of RK16331-13 LBD37 overexpressor plants and the empty vector control was determined according to the emergence of the 8th leaf blade. Three independent hybridizations were performed for line RK16331-13 and the empty vector control line.